Rust repair, where to start

[makindust]

I have a 1966 fenderside c10 that is in pretty bad shape. I've finally reached that point in life where I can get serious about restoring her. I've replaced quarter panels on cars before and have a good understanding of sheet metal fabrication, welding and painting. I've never had to replace a cab floor or cab supports etc. My question is, where do I start with regards to repairing a rusty cab. The floor is shot, the rockers are almost gone, the cab corners are rotten, the cab supports and mounts are rusted out, etc. I'm confident in my ability to repair the damage, I just don't know the proper sequence in making these repairs. Anyone willing to provide some guidance. Thanks.

[AZKen]

I need to mention that sometimes a cab is actually too far gone. You could spend way more money than buying a GMC or Chevy donor. Keep that in mind.
Not being able to access your rust, there is some engineering to think about. Figure out which repairs will cause the cab to loose symmetry. To rack, to sag, to twist due to removing structural integrity. The floors control a lot of that. The door openings MUST be kept from moving with welded or bolted struts. Google this. Get pics of what others do on all era's of vehicles. Take dozens of measurements before starting. Measurements of things you don't even think you will need. I drill small holes in door and hood hinges, like 1/8 all the way thru hinges and cab. Then when reassembling, use the drill bit as a "pin" to align while tightening the bolts. You can make Datums also. Holes, punch marks etc, to maintain a measuring point that will not be cut away.

You are entering a difficult area regarding floors AND supports AND mounts. Careful thought is necessary, including my first comment. It's pretty good practice to just tack weld and make sure associated parts will fit before final weld.

The negative of a donor cab is the VIN/Title situation.
The guy has a ton of videos on 60-66 repairs. You have to dig thru his site and follow the sequence to get to a part you are doing.
https://www.youtube.com/watch?v=oydlEWgNths

[makindust]

Thanks for the advice, I've thought about picking up a cab that is in better shape, but I'm also up for a challenge . Thanks for the advice about bracing to prevent the cab from twisting. Also the link to the YouTube videos is a great help as well.

[AZKen]

Post some pix later on.